125KHZ Mango RFID Proximity Cards ID Card Door Entry Access Card 1.8mm with running serial number. This item is Standard RFID,card not the HID card. and not for Rewritable. Original Name: Mango, with "Mango" logo on the card ! High Quality!! Proximity cards EM4100 is a great solution for access control and time attendance systems, which do not require very high security level. Easy to carry Operation frequency: 125KHZ Thickness: 1.8mm Dimensions: 85 x 54 x 1.8mm / 85.6x54x0.8mm Detecting distance: 2-10CM (Depends on the Reader) Each Card pre-programmed with unique ID which is printed on it Compatible with all RFID reader to gain access